Thermoelectric properties of PEDOT:PSS/SWCNT composite films with controlled carrier density

Previously, we developed a simple method to fabricate a composite film of a conducting polymer (PEDOT:PSS) and single-walled carbon nanotubes (SWCNTs) that exhibited high thermoelectric performance. In the present work, the carrier density of the composite film was controlled using an electrochemical method. The thermoelectric performances of the obtained composite films were analyzed in terms of their carrier densities. The electrical conductivities of the composite films were affected by the change in the carrier species of PEDOT:PSS, but overall the values were relatively high owing to the SWCNTs. The Seebeck effect showed a unique behavior reflecting the van Hove singularity in response to variations in the carrier density.